Cabin floors for larger commercial and military aircraft typically comprise a number of individual, light weight panels that are assembled together while inside the aircraft. The panels are formed from composite material having a relatively low density core and may number in excess of 100 for a typical aircraft. Each panel has four edges that may be individually sealed to the edges of adjoining panels using sealing tape, as part of the assembly process. Because the panels use a low density core, they may have limited toughness and durability, and must be carefully handled during the assembly process in order to avoid deforming the face sheets, and particularly their edges. Additionally, each panel may require multiple fasteners to secure it to the framework in the aircraft, or to the adjoining panels.
The technique described above for forming a cabin floor is not only labor intensive, but requires a relatively large number of parts, and may also require rework of the panels during the installation process. Moreover, after the aircraft is placed in service, the sealing tape may need to be replaced from time-to-time, and/or individual panels may need to be repaired or replaced, for instance, when the cabin floor carpet is replaced or partially removed in order to service aircraft systems. Finally, a cabin floor of the type discussed may have less stand-alone structural strength than a monolithic, one-piece floor because it is formed from many individual panels.
Present aircraft floors also may make installation of certain aircraft system components more difficult because the floor is installed in the aircraft before installation of the system components. The floor may therefore obstruct areas of the aircraft such as, without limitation, cargo bays, where components such as electrical boxes, wiring, ducting, and other components, are commonly installed. Assembly personnel may be required to install these system components while inside the cargo bays, where space and clearances may be tight, due in part to a previously installed overhead cabin floor that includes supporting beams extending downward into the cargo area. Thus, the installation of the system components after the floor has been installed may be difficult, time consuming, labor intensive, require numerous parts, and may require mounting the components in areas that may be less than optimal for future service and/or maintenance of the components.
Accordingly, there is a need for an aircraft floor and related aircraft assembly method that overcomes one or more of the disadvantages and limitations mentioned above. There is also a need for a unitary aircraft floor that is self-supporting, in order to reduce or eliminate the need for underlying support beams.